Abstract: A vessel for effecting multiple treatment steps needed to regenerate spent hydrocarbon conversion catalyst. Regeneration is accomplished by means of a moving bed of catalyst, where catalyst is passed through several treatment zones in the regeneration vessel. Catalyst is contacted with a hot oxygen-containing gas stream in order to remove coke which accumulates on the catalyst while it is in a hydrocarbon conversion zone. After the coke is burned off in a combustion zone, catalyst is passed into a drying zone for removal of water formed in the combustion zone which has remained on the catalyst instead of being carried off with combustion gases. Water removal is accomplished by passing a hot dry air stream through the catalyst. This air stream is introduced into the bottom of the regeneration vessel and is heated by exchange of heat with catalyst, thereby effecting the required cooling of the catalyst. Before passing into the drying zone, the air is heated further by heating means located in the vessel.

Abstract: A process for the production of motor fuel by the polymerization of aliphatic C.sub.3 and C.sub.4 mono-olefins wherein a small amount of a liquid aromatic hydrocarbon is passed through the polymerization zone to remove polymers. By-product alkylated aromatic hydrocarbons are retained in the motor fuel product as high octane components.